Helpers are the component-like classes for the presentation layer of your
application. They contain presentational logic that is shared between many
views, elements, or layouts. This chapter will show you how to configure
helpers. How to load helpers and use those helpers, and outline the simple steps
for creating your own custom helpers.

CakePHP includes a number of helpers that aid in view creation. They assist in
creating well-formed markup (including forms), aid in formatting text, times and
numbers, and can even speed up AJAX functionality. For more information on the
helpers included in CakePHP, check out the chapter for each helper:

You can pass configuration options to helpers. These options can be used to set
attribute values or modify the behavior of a helper:

namespaceApp\View\Helper;useCake\View\Helper;useCake\View\View;classAwesomeHelperextendsHelper{// initialize() hook is available since 3.2. For prior versions you can// override the constructor if required.publicfunctioninitialize(array$config){debug($config);}}

Options can be specified when declaring helpers in controller as shown:

Any configuration provided to your helper’s constructor will be merged with the
default values during construction and the merged data will be set to
_config. You can use the config() method to read runtime configuration:

Using helper configuration allows you to declaratively configure your helpers and
keep configuration logic out of your controller actions. If you have
configuration options that cannot be included as part of a class declaration,
you can set those in your controller’s beforeRender callback:

One common setting to use is the className option, which allows you to
create aliased helpers in your views. This feature is useful when you want to
replace $this->Html or another common Helper reference with a custom
implementation:

Once you’ve configured which helpers you want to use in your controller,
each helper is exposed as a public property in the view. For example, if you
were using the HtmlHelper you would be able to access it by
doing the following:

echo$this->Html->css('styles');

The above would call the css() method on the HtmlHelper. You can
access any loaded helper using $this->{$helperName}.

If you would like to render an Element inside your Helper you can use
$this->_View->element() like:

classAwesomeHelperextendsHelper{publicsomeFunction(){// output directly in your helperecho$this->_View->element('/path/to/element',['foo'=>'bar','bar'=>'foo']);// or return it to your viewreturn$this->_View->element('/path/to/element',['foo'=>'bar','bar'=>'foo']);}}

By implementing a callback method in a helper, CakePHP will automatically
subscribe your helper to the relevant event. Unlike previous versions of CakePHP
you should not call parent in your callbacks, as the base Helper class
does not implement any of the callback methods.

Is called after each view file is rendered. This includes elements, views,
parent views and layouts. A callback can modify and return $content to
change how the rendered content will be displayed in the browser.